Method for Acquiring Fault Information of Planetary Gearbox

Abstract

The invention discloses an epicyclic gear box fault information acquisition system and a method thereof. The system comprises an inner gear ring, a planetary gear and a sun gear, wherein the inner gear ring, the planetary gear and the sun gear together form an epicyclic gear box. The inner gear ring is immobilized. The sun gear is rotating around the central axis thereof. The planetary gear orbits around the sun gear while revolving on its axis. A plurality of successive gear teeth on the inner gear ring are adopted as detection teeth. A fiber bragg grating array is stuck onto the tooth root parts of the detection teeth. The light emitted from a broadband light source is transmitted to the fiber bragg grating array via an optical fiber a, a coupler and an optical fiber c. The reflected light passes through optical fiber c, the coupler and an optical fiber b to enter a wavelength demodulation part. After the demodulation process, a voltage signal is subjected to the data processing treatment by a computer through a data acquisition part. The computer constructs a tooth root strain sequence and extracts the fault information of the epicyclic gear box. According to the technical scheme of the invention, the defect in the prior art that due to the nonlinear and non-stable characteristics of vibration signals, the fault of the epicyclic gear box is hard in diagnosis can be overcome.

Description

technical field [0001] The invention relates to a dynamic test and fault diagnosis technology of a mechanical transmission device, in particular to a method for acquiring fault information of a planetary gearbox. Background technique [0002] Due to the advantages of small size, light weight, high transmission efficiency and strong load capacity, planetary gearboxes are widely used in mechanical transmission systems in aviation, wind power generation, lifting transportation, energy and other fields. Due to the impact of the harsh working environment under load, the probability of failure of the planetary gearbox is very high. Since the planetary gearbox is located in the key link of the mechanical system, when it fails, if effective remedial measures are not taken in time, it will affect the system performance at least. If it is serious, it will paralyze the system and cause serious accidents. Therefore, it is of great significance to carry out fault diagnosis on planetary g...

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Problems solved by technology

[0002] Due to the advantages of small size, light weight, high transmission efficiency and strong load capacity, planetary gearboxes are widely used in mechanical transmission systems in aviation, wind power generation, lifting transportation, energy and other fields. Due to the impact of the harsh working environment under load, the probability of failure of the planetary gearbox is very high. Since the planetary gearbox is located in the key link of the mechanical system, when it fails, if effective remedial measures are not taken in time, it will affect the system performance at least. If it is serious, it will paralyze the system and cause serious accidents. Therefore, it is of great significance to carry out fault diagnosis on planetary gearboxes.

[0003] At present, most researchers at home and abroad judge the health status of the planetary gearbox through the analysis and processing of the vibration signal. The vibration sensor is installed on the box connected to the inner ring gear. The main advantage of using the vibration signal as the fault carrier signal is that Its measurement is simple, real-time, and contains rich fault information. However, the vibration signal of the planetary gearbox is more complex than that of general mechanical equipment: multiple meshing vibrations are coupled with each other and the vibration signal is modulated by the transmission path, resulting in The vibration signal measured by the sensor contains a variety of frequency components and rich sideband information, showing strong nonlinear characteristics; variable speed and variable load conditions lead to changes in the gear meshing frequency and fault characteristic frequency in the vibration signal, showing Due to the above reasons, although scholars at home and abroad have done a lot of work in dynamic modeling and vibration signal processing, the fault diagnosis of planetary gearboxes is still a technical problem

[0004] In fact, the most critical movement in a planetary gearbox is the meshing movement between the gears. The meshing force is the most direct parameter that can reflect the meshing state and characteristics of the gears. However, the meshing force is generated by the mutual contact and extrusion of the gear teeth. Sensors are arranged in the contact area of ​​the gear teeth to measure the force, so the researchers choose the vibration signal to indirectly reflect the change of the meshing force, but the mapping relationship between the meshing force information and the vibration information in the planetary gearbox is very complicated, resulting in the emergence of planetary gears. Considering that the distance between the tooth root area and the meshing area is very close, the change of the meshing force will directly lead to the change of the tooth root strain, so compared with the vibration signal, the tooth root strain signal can better reflect the gear The meshing state is a more high-quality fault characteristic carrier signal. However, so far, the fault diagnosis method of planetary gearbox based on the tooth root strain signal has not been reported.

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